Vacuum operated debarking apparatus



June 15, 1965 F. DILLINGHAM VACUUM OPERATED DEBARKING APPARATUS 1O Sheets-Sheet 1 Filed June 16, 1961 ATTORNEYS June 15, 1965 F. L. DILLINGHAM VACUUM OPERATED DEBARKING APPARATUS Filed June 16, 1961 10 Sheets-Sheet 2 v INVENTOR FIG. 2 FREDERICK L. DILLl/VGHAM ATTORNEYS June 15, 1965 F. L. DILLINGHAM 3,189,067

VACUUM OPERATED DEBARKING APPARATUS Filed June 16 1961 1p Sheets-Sheet 4 INVENTOR F RE DER/0K L. BILLING/MM ATTORNEYS June 15, 1965 F. L. DILLINGHAM 3,189,067

VACUUM OPERATED DEBARKING APPARATUS Filed June 16, 1961 10 Sheets-Sheet 5 I ATTORNEYS June 15, 1965 F. DILLINGHAM 3,189,067

VACUUM OPERATED DEBARKING APPARATUS Filed June 16, 1961 10 Sheets-Sheet 6 FREDERICK L. BILLING/1AM June 15, 1965 F. L. DlLLlNGHAM 3,189,057

VACUUM OPERATED DEBARKING APPARATUS Filed June 16, 1 961 10 Sheets-Sheet 7 INVENTOR F REDERIGK L. DIL L/IVGHAM ATTORNEY-5 June 15, 1965 F. DILLINGHAM 3,189,057

VACUUM OPERATED DEBARKING APPARATUS Filed June 16, .1961 v 1o Sheets-Sheet a I I'l I'l I 9 I'll I i l| mv- I WI QQ E S N M I \Ll II I I l 1' |I l l l: N |||ll 9 3 1M3 IN I 'l g 'l- :w I

I H I Ink INVENTOR FREDERICK L. DILL INGHAM ATTORNEYS June 15, 1965 F. L. DlLLlNGHAM 3,139,057

VACUUM OPERATED DEBARKING APPARATUS Filed June 16, 1961 10 Sheets-Sheet 9 FIG. [4

a, 1 INVENTOR Fnsa'mcx L. mum/mu June 15, 1965 F. L. DILLINGHAM VACUUM OPERATED DEBARKING APPARATUS l0 Sheets-Sheet 10 Filed June 16, 1961 INVENTOR FREDERICK L. BILL/"6H4" ATTORNEYS United States Patent O 3,139,067 VACUUM OPERATED DEBARKING APPARATUS Frederick L. Dillingham, Sylacauga, Ala, assignor to "Soderhamn 'Machine Manufacturing Company, Talladega, Ala.

Filed June 16, 1961, Ser. No. 117,585 1'7 Claims. (Cl. 144-268) This invention relates to woodworking and more particularly to a debarking apparatus of the rotary type which operates to remove all bark from a log as the same passes axially therethrough.

Heretofore numerous types of debarking apparatus have been proposed and utilized and certain of these have been of the so-called rotary type in which a log is fed axially through the apparatus and debarking tools are rotated around the log in a manner to cut or scrape the bark from the surface of the log. While these prior art machine's have operated more or less satisfactorily to remove bark from a log, nevertheless, difficulties have been expelienced, particularly with regard to the control'and operation of the bark removing tools and also in the apparatus for feeding the log to the debarking apparatus in a manner to properly locate and center the log with respect to the debar king apparatus and to prevent rotation of the log during the debar-king operation, or in the event rotation does'occur, to prevent such rotation from moving the log out of axial alignment with the deb-ark-ing apparatus.

In many of the prior art rotary debarking machines, the bark removing cutters are carried by a rotary head through which the log moves axially and means is provided to cause enga-gementof the cutters wi-th the surface of the log in order to cut or scrape the bark therefrom. It is common practice to mount the debarking cutters or scrapers in the debarking head in such a manner that the same are capable of inward and outward radial movement usully provided by mounting the cutters on a shaft which in turn is rotatably mounted in the debarking head and the cutters are normally held in engagement with the surface of the log by fluid pressure means in the form of pistons and cylinders in which the cylinders are mounted in the debarking head and the pistons are connected either to the tool mounting shaft through a'suitable lever arm or directly to the bodies of the tools themselves. Fluid pressure cylinders and pistons are, of necessity, relatively heavy and furthermore, adequate lubrication is required for proper operation and extreme care must be exercised to prevent leakage of fluid pressure between the piston and the cylinder wall and likewise, at the point where the piston rod extends through the cylinder head. Furthermore, suitable pivotal mounting must be'provided for the cylinder or a suitable linkage must be provided between the piston and the tool to be actuated thereby in order .to permit proper operation of the cylinder and piston and'this, of course, results in a relatively costly structure which is difficult and expensive to maintain or replace in the event of failure or damage. Furthermore, due to the relatively large Weight of fluid pressure cylinders and pistons, the question of centrifugal force and inertia plays an important part, particularly where such structure is in stalled in a debark-ing head which rotates at a relatively high speed. The centrifugal force developed by the piston and elements attached thereto during rotation of the debarking head materially affects the operation of the fluid pressure piston and cylinder in controlling the operation of the debarking tools, since the fluid pressure employed must be suitably adjusted to compensate for the centrifugal force developed during operation of the apparatus. Furthermore, the relatively high inertia of the piston and elements connected thereto tends to reduce the speed of response of the tool to changes in the contour or surface of the log with which the same is in contact and in extreme 3,l89,@67, Patented dune l5, 1%65 cases, the inertia is such as to prevent the tool from following such contour accurately, thereby causing a momentary failure of the bark removing tools resulting in the necessity of reversing the feeding apparatus to again pass a portion of the log through the debarking apparatus in an attempt to complete the removal of bark therefrom.

A further troublesome factor in connection with prior art rotary debarking machines is the difficulty of control ling .the action of individual bark removing tools in such a manner that one tool mayvrapidly move to accommodate changes in log surface contour Without materially affecting the position or pressure exerted by other tools on the surface of the log and one attempt has been made to over come this difficulty by utilizing fluid pressure cylinders for controlling each of the d-ebarking tools and by having all of the cylinders in substantially free communication with a common fluid pressure reservoir. While it might seem at first glance that such a solution to the problem is entirely feasible, nevertheless, the same has not proven entirely satisfactory, in that upon movement of one tool with a consequent movement of the piston connected thereto, the pressure in the common fluid pressure reservoir is immediately raisedand such higher pressure is immediately communicated to the other cylinders and pistons resulting in changing the pressure on the clebarking tools conected thereto. Furthermore, this immediate build up of pressure results in unduly resisting movement of a tool to accommodate for relatively quick changes in log surface contour with the result that the cutting tools have a tendency to dig in at certain points thereby materially and adversely affecting the quality of the debarlo ing operation. 1

In rotary deba king machines heretofore utilized, it has been customary to design the debarking tools in such a manner that contact of the leading end of the log'advancing through the apparatus operates to move the tools radially outwardly a distance depending upon the diameter of the log and thereafter, the cutting portions of the tools engage the sur-faceof the log to remove bark therefrom until such bark removal operation is completed. -I-low ever, upon the trailing end of the log passing out of em gagement with the debark-ing tools, the same immediately move rapidly or snap into an inoperative inner position which results in considerable shock to the apparatus and in certain instances, can easily result in failure of certain parts of the apparatus, such as keys and other connecting or coupling members.

The problem of properly feeding a log to rotary deba-rkin'g apparatus has also presented somewhat of a problem, in that in order to provide proper debarking, the log must be substantially centered with respect to the axis of the debarlring apparatus and furthermore, since the operation of the debarking tools tends to rotate the log, if such rotation actually takes place, there is immediate danger 'of the log being rolled out of alignment with the longitudinal axis of the deba-rkin-g apparatus. As a consequence, it has been found necessary to provide means for moving a log into a position in alignment with the longitudinal axis of the debarking apparatus and to maintain the log in such position, even though rotation thereof may possibly take place and it has been found that this may be accomplished by novel design of certain of the feeding rolls, as well as novel design of a pressure roll which serves to maintain the log in feeding contact with the feed rolls.

Briefly stated, the present invention operates to overcome the disadvantages .set forth above in debarking apparatus of the type under consideration, by controlling the operation of the debarking tools from a flexible diaphragm which is provided as a partition in an actuating chamber provided in the debarking head. Where four debarking tools are provided the same are rigidly mounted on tool shafts which in turn are rotatably mounted in the debarking head and each shaft is provided with an actuating arm which is connected through a flexible member, such as a chain, with the actuating diaphragm. The actuating chambers are radially disposed in the debarking head andwhere four such chambers are utilized, the sam are normally angularly spaced ninety degrees apart and between each pair of actuating chambers there is provided a vacuum chamber. A novel means is utilized to provide for simultaneous operation of all of the diaphragms to apply force to the debarking tools urging the same inwardly against the surface of a log and also at the same time, to permit substantially independent operation of each tool in .a radial direction to compensate for irregularity or changes in the surface contour of the log and such independent motion or operation of a single tool may take place without in any way materially affecting the operation of the other tools or the force exerted thereon by the respective dia-' phragms. This operation is provided for by a relatively small aperture connecting one actuating chamber with an adjacent vacuum chamber and by means of a relatively large aperture connecting the same actuating chamber with the other adjacent vacuum chamber. hose two apertures provide communication between all of the actuating chambers and all of the vacuum chambers in order to apply vacuum to all of the diaphragms and prior to engagement of the cutting tools with a log, equilibrium will obtain, in that the negative pressure in each actuating chamber will be substantially the same. However, upon contact of one of the tools with a raised portion on the log, the diaphragm connected thereto will immediately move thereby changing the pressure in the actuating chamber and such pressure following the path of least resistance will change the pressure in the vacuum chamber communicating therewith through the relatively large aperture but will not have any material effect on the pressure in the vacuum chamber communicating therewith through the aperture of relatively small cross section. This novel structure results in smooth and satisfactoryoperation of the debarking tools.

Furthermore, by the use of diaphragms, rather than pistons and cylinders, the weight of the apparatus has been materially reduced with a consequent reduction in inertia and centrifugal force developed during operation of the apparatus and furthermore, fluid pressure leakage and the need for lubrication has been eliminated and a simple connection between the diaphragm and the tool shaft provided by a flexible element, such as a chain may be utilized, rather than a more complex and costly linkage or connecting rod system. It has also been proposed by this invention to design the debarking tools in such a manner that shock will be reduced or substantially prevented at the moment when the tools leave the trailing end of a log on which the debarking operation has been completed.

It is accordingly an object of the invention to provide a debarking apparatus of the rotary type which may be conveniently and economically constructed from readily available materials and which will operate to satisfactorily remove the bark from a log, regardless of the surface irregularities present thereon.

Therefore, consistent with the aforegoing object, it is a principal object of this invention to provide a debarking machine of the rotary ring type which includes a plurality of debarking tools carried by the ring and mounted for movement toward and away from the axis thereof and vacuum operated tool actuating means operably connected to the tools for moving the same toward the axis of the ring to effect the debarking whereby the tools are applied against a log to be debarked with sufiicient pressure to remove the bark with the resultant advantage attributable to vacuum operation that the tools are independently operable so that if one tool strikes a projection the resultant movement thereof away from the axis of the ring is not transmitted to the others.

A further object of the invention is the provision of a debarking apparatus of the rotary type in which a rotary head is mounted in a frame which is adjustable vertically to center the same with respect to a log and in which the rotary head is yieldably mounted in order to compensate for small errors in alignment between the log and the head and also to reduce shock.

A still further object of the invention is the provision of a debarking apparatus of the rotary type, including. a rotatable debarking head'rotatably and yield-ably mounted in a frame and in which such head is frictionally driven in a manner to provide adequate driving power, but which drive will provide for slippage in the event the debarking head becomes locked against rotation thereby preventing damage to the apparatus.

A further object of the invention is the provision of a debarking apparatus of the rotary type, including a ro- 'tatable debarking head which may be conveniently fabricated from metal plates of suitable gauge to provide a structure of .ring shape having a central aperture therethrough for passage of a log and in which partitions are positioned within the head to provide actuating chambers and vacuum chambers.

A still further object of the invention is the provision of a debarking apparatus of the rotary type, including a rotatable debarking head of generally ring shape and having a central opening for passage of a log therethrough, there being actuating chambers and vacuum chambers in the head with a diaphragm installed in each actuating chamber and debarking tool-s mounted on shafts rotatably mounted in the debarking head, such shafts being suitably connected to the d-iaphragms for operation thereby to move the debarking tools radially inwardly.

A still further object of the invention is the provision of a debarking apparatus of the rotary type, including a rotatable debarking head on which are mounted debarking tools for radial inward and outward movement, such tools :being urged inwardly by diaphragms subjected to vacuum in an actuating chamber, each actuating chamber communicating with an adjacent vacuum chamber through an aperture of relatively small cross section and also communicating with another adjacent vacuum chamber through an aperture of relatively large cross section.

Another object of the invention is the provision of a debarking apparatus of the rotary type, including a rotatable debarking head on which are mounted debarking tools for radial inward and outward movement, such tools being urged inwardly by vacuum operated diaphragms, each tool being operable in response to outward pressure thereon by irregularities in the log surface entirely independently of the other tools and without in any way materially changing the force exerted on the other tools.

A further object of the invention is the provision of a debarking apparatus of the rotary type, including a 1'0- tatable debarking head on which are mounted debarking tools for radial inward and outer movement the pressure or force exerted on such tools urging the same inwardly bemg provided by vacuum actuated diaphragms thereby eliminating the necessity for packing or packing glands to eliminate leakage.

A still further object of the invention is the provision of a debarking apparatus including a rotatable debarking head having debarking tools mounted on shaft-s rotatably carried by the head, such tools being urged radially inwardly by vacuum operated d-iaphragms which are conneoted to the tool shafts by flexible means, the diaphragm structure and means providing for connection with the operating shafts being of a novel character.

A further object of the invention is the provision of a cutting tool for a debarking apparatus of the rotary type such tool including means to permit movement of the tool outwardly into engagement with the surface of a log and means to permit gradual inward movement of the tool upon completion of the debarking operation thereby reducing shock to a minimum.

Another object of the invention is the provision of a cutting tool for rotary debarkingapparatus, such tool having means for engaging the leading end of a-log to cam the tool outwardly into engagement with the surface of the log forperforming a debarking operation and also having means for engaging the trailing end of the log to cam the tool inwardly at a relatively slow speed in order 7 to reduce shock upon completion of the debarking operation.

A further object of the invention isthe provision of a debunking tool for a rotary debarking apparatus in which a cutter base having a relatively hard cutter bit fixed thereto is removably mounted in the end of the debarking tool to permit convenient replacement of the cutting portion.

A still further object of the invention is the provision of a feeding mechanism for a rotary debarking apparatus which will operate to properly position and feed a log for debarking by the debarking apparatus.

Another object of the invention is the provision of a feeding mechanism for a rotary debarking apparatus in which means is provided for normally preventing rotation of the log during the debarking operation and in which means is also provided for moving thelog laterally to a centered position and maintaining the same in such position.

A further object of the invention is the provision of a feed roll for the feeding mechanism of a rotory debarking apparatus, such feed roll including radially extending vanes providing a concave log engaging surface with one side of the concave surface being serrated to provide traction and prevent rotation of the log.

A still further object of the invention is the provision of a pressure roll for the feeding mechanism of a rotary debarking apparatus, such pres-sure roll including opposed cones diverging outwardly to provide a concave log engaging surtace and with the log engaging surface of one cone formed with a plurality of parallel ribs in order to engage a log which is on" center and cause movement of the same laterally to a centered position.

Further objects and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawings wherein:

. FIG. 1 is a front elevational View showing the base and mountingframe for a rotatable deb-arking head, toget-her with the means for rotatably mounting the head in the frame and for driving the rotary head;

FIG. 2'is a side elevational view of the base and supporting frame, as well as the drive motors and mounting means for the rotatable deba-rking head shown in FIG. ll;

FIG. 3 is a front elevational view similar to PEG. 1 but showing in addition thereto the feeding mechanism for feeding a log to the debarking cutters carried by the rotatable debarking head;

FIG. 4 is a side elevational view showing the debarking apparatus, as well as the feeding means for feeding a log thereto and the conveying means for receiving a log upon completion of the debark-ing operation;

FIG. 5 is a sectional view through the debarking head and showing the internal structure thereof and particularly-the mounting and arrangement of the actuating diaphragms, as well as the connection between suchdiap'hragrns and the tool shafts on whichare mounted the debarking tools and showing such debarking tools in inoperative position; i

FIG. 6 is .a sectional View similar to FIG. 5, but showing the debarking tools in operative position and with a log passing through the central opening of the debarking head;

FIG. 7 is .a front elevational view showing the details of the base and the mounting frame for the rotary debarking head;

FIG. 8 is a side elevationalview of the base and head mounting frame shown in FIG. 7;

BIG. 9 is a sectional view of the debarking head, similar to FIG. 5, but eliminating the diaphragms and tool shafts, aswell as the deba-rking tools and showing modi-' tied details of the structure of the debarking head as viewed from the side opposite FIG. 5;

FIG. '10 is a sectional viewtaken substantially on the line lit-16 o-f'FlG. 9 and showing a portion of theinternal structure of the debarking head;

FIG. 11 is a front elevational view showing tuating arm for one of the tool shafts;

FIG. 12 is a side elevational view showing further details of the actuating arm shown in FIG. '11;

FIG. 13 is a front elevational View of one of the debarking tools;

FIG..14 is a side elevational view of the debarking tool shown in FIG. 13;

MG. is a fragmentary front elevational view showing the details of the mounting means for the cutter base and cutter bit on the debarking tool of FIG. 13;

FIG. 1-6 is a front elevational view of one of the feed rolls forthe debarking apparatus of this invention; and

' FIG. 17 is a front elevational view of one of the pressure rolls for the feeding apparatus of this invention.

. With continued reference to the drawings and particularly FIGS. 1, 2, 7 and 8, there is shown a debarking apparatus constructed in accordance with this invention and which may well comprise a rectangular base It) constructed of any suitable material and adjacent one end of the base it there is provided an upstanding bracket L1 in the form of spaced plates 12 and 13 of-generally triangular configuration. A frame 14 constructed primarily of spaced plates 15 and 16 is pivotally mounted at one end by means of a-pivot pin 17 on the upper end of the bracket 11 and as best shown in FIG. 1, the frame 14 overhangs the base it). The frame 14 terminates at the end opposite the pivot pin 17 in a generally ring shaped portion 13 and provided within the ring shape portion is a transverse horizontal opening 19 for a purpose to be later described.

As best shown in FIGS. 7 and 8, the frame 14- is rethe acinforced by a tubular member 2 3' secured in place between the plates 15 and 16 and at the inner end of the tubular member 2a adjacent the opening 19 there is provided an car 21. Below the car 21 and in alignment therewith when tubular member 26 is horizontal is an ear 22 secured to the lower end of the bracket 11 and base 10, as by welding or the like, and the car 22 is provided with an aperture 23 for receiving a pin 2-4 which serves to pivotally mount a fluid pressure cylinder 25 and the pis-ton'rod, not shown, of the cylinder 25 is pivotally connected by a pin, also not shown, passing through an aperture 26 in the ear 2 1 on the frame 14. Operation of the fluid pressure cylinder v2% serves to pivotally move the frame 14 in a vertical plane about the pivot pin 17 and the purpose of this vertical movement will later appear. i

A deha-rking head 27 is rot-stably mounted in the opening 19 in the ring shaped portion 18 of the frame 14 and as best shown in FIGS. 9 and 10, the de'barking head 27 is formed by an inner shell 28, an outer concern trio shell 29 and end plates 30 and 3 1. The inner and outer shells 28 and 29, as well as the end plates 30 and 31 are welded or otherwise secured together to provide a ring shaped structure of the type particularly shown in FIG. 9 and this structure also serves to provide a central horizontal opening 312 through the debarking head 2-7 and such opening 32 provides for passage of a log therethrough in a manner to belater described.

. Pairs. of yieldable rollers 33, 34, 35 and 36 are rotatably mounted on the frame 14 and these rollers serve to engage the outer shell 29 of the debarlr-ing head 27, as clearly shown in FIGS. 1 and 2, to rotatably and yieldably mount the head 27 within the opening 19 of the frame 14. As a consequence, the head 27 may freely rotate within the opening 1-9 of the frame 14 and likewise, due to the yieldability or resiliency of the mounting rollers, the head 27 may move a limited amount in a radial direction to compensate for minor misalignment and the yieldability of the mounting rollers also serve to reduce shock. Diametrically disposed yielda-ble thrust rollers 37 and 38 are rotatably mounted on the frame 14 adjacent fne top .and bottom thereof respectively, and theroll'ers 37' and 38 engage the end plate 31 of the head 27 to prevent axial movement of the same toward the left as viewed in FIG. 2. Spaced ninety degrees from the rollers 3-7 and 38 and rotatably mounted on the ring 1 shaped portion 18 of the frame 14 is a thrust roller 39 which engages the end plate of the head 27 to prevent axial movement of the head 27 toward the right as viewed in FIG. 2.

Y Brackets 4'0 and 41 are mounted on opposite sides of the frame 14, the bracket 40 being secured to the plate 16 while the bracket 41 is secured to the plate 15. Mounted on the bracket 40 is drive motor 42 and mounted on the bracket 41 is a similar drive motor 43. Drive motors 42 and 43 are provided with friction drive wheels 44, one of which engages the end plate 30 of the head 27 and the other engages the end plate 31 on the opposite side of the head 27. It will be noted that as shown in FIG. 1, the friction drive wheels 44 are disposed diametrically opposite the thrust roller 39 and consequently, the friction drive wheel 44 on the motor 43 in conjunction with the thrust roller 39 prevents axial movement of the head 27 toward the right as viewed in FIG. 2. Operation of the drive motors 42 and 43 serves to drive and rotate the head 27 within the opening 19 of the frame 14 by reason of the frictonal engagement between friction driving wheels 44 and the end plates 30 and 31 of the head 27 and this driving engagement is sufiicient for all normal debarking operations, but in the event the debarking head 27 becomes jammed for any reason the friction drive means will slip thereby preventing damage to the apparatus.

. With particular reference to FIGS. 5, 6, 9 and 10, the debarkiug head 27 as mentioned above, is a hollow generally ring shaped structure and within the head 27 there are provided partitions 45, 46, 47, 48, 49, 50, 51 and 52 extending between the outer shell 29 and the inner shell 28 and secured thereto as well as to the end plates 30 and 31 by welding or the like to provide fluid tight seams. Partitions 45 and 46 serve to provide a radially disposed actuating chamber 53 and in a similar manner, partitions 47 and 48 provide an actuating chamber 54, partitions 49 and 50 and actuating chamber and partitions 51 and 52 and actuating chamber 56. Partitions 45 and 52 provide a vacuum chamber 57 between the actuating chambers 53 and 56, partitions 53 and 47 provide a vacuum chamber 58 between actuating chambers 53 and 54, partitions 48 and 49 provide a vacuum chamber 59 between actuating chambers 54 and 55 and partitions 51 and 50 provide a vacuum chamber 60 between actuating chambers 55 and 56.

Since the structure in each of the actuating chambers 53, 54, 55 and 56 is identical, such structure will only be described in detail in connection with actuating chamber 53 and as best shown in FIG. 5, a plate 51 having a central opening is secured to the partitions 45 and 46, as well as to the end plates 30 and 31 intermediate the length of the partitions 45 and 46 and a clamping ring 62 secured to the plate 61 by screw threaded fastening means or the like 63 serves to firmly secure the outer periphery of a diaphragm 64 formed of suitable flexible air impervious material to the plate 61. As a result, the diaphragm 64 serves to divide the actuating chamber 53 into an inner chamber 65 and an outer chamber 66. Centrally of the diaphragm 64 and on opposite sides thereof there are provided disks 67 of metal or other suitable rigid material and such disks are firmly secured to the diaphragm 64 by rivets 68 or other suitable securing means. The inner disk 67 is provided with an outwardly extending lug means 69, the purpose of which will be presently described.

The outer chamber 66 is connected to the vacuum chamber 58 through an aperture 70 of relatively small cross section and the outer chamber 66 is also connected to the vacuum chamber 57 through an aperture 71 of relatively large cross section. In asimilar manner, outer chamber 72 is connected to vacuum chamber 59 through an aperture 73 of relatively small cross section and is also connected to vacuum chamber 58 through an aperture '74 of relatively large cross section. Outer chamber 75 is connected to vacuum chamber 60 through an aperture 76 of relatively small cross section and to vacuum chamber 59 through an aperture 77 of relatively large cross section, while outer chamber 78 is connected to vacuum chamber 57 through an aperture 79 of relatively small cross section and to vacuum chamber 60 through an aperture 80 of relatively large cross section. The purpose and operation of these connecting apertures of dilferent cross sections will be later described.

A tool shaft 81 is rotatably mounted in end plates 30 and 31 and extends through inner chamber 65 and tool shaft 82 is rotatably mounted in end plates 30 and 31 and extends through inner chamber 83. In a similar manner, tool shafts 84 and 85 are rotatably mounted in end plates 30 and 31 and extend through inner chambers 86 and 87 respectively. Fixed to the tool shafts 81, 82, 84 and 85 within the inner chambers 65, 83, 86 and 87 are actuatingarms 88, the structure of which will be later described, and also fixed to the ends of the tool shafts 81, 82, 84 and 85 extending outwardly of the end plate 30 are debarking tools 89, the structure of which will also be later described.

With particular reference to FIGS. 11 and 12, each of the actuating arms 88 may well comprise a hub 90 having a bore 91 therethrough for receiving the associated tool shaft and the hub 90 may be provided with a keyway 92 for receiving a key 93 as shown in FIG. 5, to prevent relative rotation between the arm 88 and the tool shaft.

The hub 90 may be split as shown at 94 and outwardly extending ears 95 and 96 may be provided with aligned apertures 97 and 98 for receiving screw threaded fastening means 99 provided with a head 100 at one end engaging the ear 95 and a nut 101 at the opposite end engaging the ear 96 to securely clamp the hub 90 on the tool shaft. Projecting radially outwardly from the hub 90 is boss 102, the outer peripheral surface 103 of which is arcuate and concentric with the axis of the hub 90 and the tool shaft. As best shown in FIG. 12, the outer portion of the boss 102 is reduced in thickness to provide an arcuate rib 104 terminating in inner arcuate shoulders 105 and 106 which are also concentric with the axis of the hub 90 and the tool shaft. The opposite sides of the rib 104 are connected to the peripheral surface 103 of the boss 102 by beveled surfaces 107 and 108. The boss 102 is provided with an aperture 109 therein of the arcuate rib 104 and purpose of the aperture 109 will be presently described.

With particular reference to FIG. 5, a chain 110 may have one end 111 thereof connected to the stud or lug 69 on the plate 67 secured to the diaphragm 64 and the pin 112 on the opposite end of the chain 110 may pass through the aperture 109 in the boss 10-2 of the actuating arm 88 to secure the chain 110 thereto. Obviously, the rollers or pins of the chain 110 will engage the arcuate peripheral surface 103 of the boss 102 on the actuating arm 88 and the side links 113 of the chain 110 will overlap the side surfaces of the rib 104 to maintain the chain 110 in substantial alignment. Since the arcuate surface 103 is concentric with the axis of the hub 90 and the axis of the tool shaft movement of the diaphragm 104- and the movement of the actuating arm 88 connected thereto by the chain 110 will result in the chain 110 maintaining substantially a straight line with respect to the diaphragm 64 thereby preventing undue tilting of the 9.; same during operation and the chain 111) also provides a relatively inexpensive, yet highly effective means for connecting the actuating arm and the diaphragm 64.

While as mentioned above, the debarking head 27 includes inner and outer shells 2d and 2%, the inner shell 28 may if desired, be continuous or may be interrupted to provide openings into the inner chambers 65, 83, $6 and 57 and such chambers may be closed by removable cover plates 11 i, 115, 1:16 and 117, but since the inner chambers 65, 33, S5 and 87 are closed and since it is desired that no resistance to movement of the diap-hragms 64 be provided, vent openings 11% may be provided in the end wall 36 or 3 1 to prevent a rise in pressure in the inner chambers 65, 53, 36 and 87 thereby allowing for free movement of the diaphgrams 64 under the action of vacuum in the outer chambers 66, 2, and 75. Also in order to permit the application of vacuum to the vacuum chambers 57, 58, 59 and 6%, as well as the outer chambers 66, 72, 75 and 78, a suitable aperture 1119 provided with a fitting for connection of a vacuum line thereto may be provided in either end wall 31 or 31 and communicate with the vacuum chamber 57 as shown in FIG. 5, or if desired, such vacuum connection may be provided in any of the other vacuum chambers 58, 59 or 61 With particular reference to FIGS. 13, 14 and 15 the debarlring tool 89 utilized in connection with the debarking apparatus of this invention may well comprise a hub 12%? which is fixed to the tool shaft 251 in any suitable manner and projecting from the hub 12% and at right angles to the axis of the bore 121 extending therethrough is an elongated curved body 122. The body 122 is of generally T-shape in cross section which is provided by opposed flanges 123 and 12d and by an outwardly projecting rib 12:5. The body 122 terminates in a cutter receiving portion 126 of generally rectangular cross section. The flange 123 is tapered outwardly from the hub 12-11 to the cutter receiving portion 126 and the edge 12') of the flange 123 follows a substantially uniform curve to provide a cam surface on the leading edge of the debarking tool 89 for a purpose to be later described. The flange 124 on the body 122. is also tapered outwardly from the inner end of the body 122 adjacent the hub 12% to the cutter receiving portion 126, but it is to be noted that the outer edge portion 12% of the flange 124- is formed on a relatively fiat curve, while the inner portion 129 of the edge of the flange 124- is provided with a substantially greater curvature and terminates at a point 131) spaced from the hub 1211. The portion 123 occupies substantiallytwo-thirds of the length of the flange 124 while the portion 129 occupies substantially the remaining one-third of the length thereof and the curved portions and 12% senve to provide a trailing cam surface on the flange 124, the purpose of which will be later described. An car 131 projects outwardly from the body 1222 adjacent the hub 1211 and between the end of the flange 124 and the hub 12% and provides means for engaging a stop member 132 provided on the end plate 30 as shown in FIG. 2, to limit inward movementof the debark-ing tools 89.

With particular reference to FIG. 15, the cutter receiving portion 126 of the debarking tool 89 is provided with a generally rectangular recess 133 and communicatwith the rectangular recess 133 is a circular recess 154. A cutter base 135 is removably disposed in the rectangular recess 133 and the cutter base 135 is provided with a circular boss 136 disposed in the circular recess 134 and the depth of the circular recess 134 is greater than the height of the boss 1%, as clearly shown in FIG. 15. The circular boss 136 is provided with a threaded recess 137 which serves to threadedly receive a screw threaded fastening member 158 projecting through an aperture 139 in the cutter receiving portion 126 of the debarking tool 85 and the head 1413 of the screw threaded fastening member 13 5 is received in a counter bore 141 in the cutter receiving portion 126. The screw threaded fastening member 139 serves to releasably retain the cutter base 135 in the rectangular recess 13 3. A cutter bit 142 of suitable hard material, such as tungsten car-bide may be secured by suitable means in a rectangular recess 143 provided in the cutter base 135 and the entire cutting or debarking function is performed by the cutter bit 142. In the event the bit 142. becomes dull or worn, it is only necessary to remove the screw threaded fastening means 138 thereby permitting removal of the cutter base 135 and cutter bit 112 attached thereto and replace the same with another cutter base and new bit in order to place the apparatus in condition for further and efiicient operation.

Log feeding mechanism is provided and such feeding mechanism may well comprise upright side frame members 14-4 and extending upwardly to a point well above the frame 14 of the debarking apparatus and connected at the top by a cross member 1%. Longitudinal frame members 14-7 are secured to the side frame members 144 and 145 and the longitudinal frame members 147 serve to support a plurality of spaced feed rolls 148 and 149 and while only two such feed rolls are shown in F167 4, obviously additional feed rolls will be provided in order to properly support a log being fed to the debarking apparatus, but since the feed rolls 148 and 14 9 are typical, it is believed only necessary or desirable to show such feed rolls and to describe the structure and operation thereof. The feed rolls 148 and 14 9, as well as the necessary additional feed rolls are driven in any suitable manner, as by chains engaging sprockets 149, in order to feed a log toward the debarking apparatus. It is to be noted, that the upright frame members 144- and 14 5 are disposed between the feed rolls 14 3 and 14 9 and 'slidably mounted on the side frame members 14-4 and 145 above the feed rolls 148 and 149 is a cross head 15d and rotatably mounted on the cross head 15% is a pressure roll 151. A fluid pressure cylinder 152 is mounted on the upper cross member 14-6 and the piston rod 153 of the fluid pressure cylinder 15?. is connected to the cross head 15%) in order to raise or lower the same and at the same time, raise or lower the pressure roll 151.

With particular reference to FIG. 16, there is shown the detailed structure of the feed roll 148 and a description of this feed roll will also suffice for a description of the feed roll 14:9 and as well as certain other of the feed rolls provided and as shown in FIG. 16, the feed roll 14% may well comprise a roll shaft 154 which may, if desired, be tubular and be provided with suitable bearings 155 at the ends thereof and if desired, the bearings 155 may be in the form of bushings to be received on a supporting shaft and secured to the outer surface of the roll shaft 154 by welding'or by any other suitable means are a plurality of angularly spaced radially projecting vanes 156 and 156 disposed longitudinally of the roll shaft in staggered relationship 15d and the vanes 156 and 156' serve to provide an outwardly opening generally V-shaped notch 157 with the apex 158 thereof substantially at the midpoint of the roll 148. The surfaces 159 of the vanes 156 at the right hand side of the apex 153 of the notch 157 as shown in FIG. 16, are'smooth, while the surfaces of the vanes 156' on the opposite side of the apex 158 of the notch 1157 are provided with longitudinally spaced serrations 160, the purpose of which will be presently described. The feed rolls 148 and 149, as well as certain other of the feed rolls are arranged in the feeding mechanism in such a manner that all of the smooth surfaces 159 are on one side of the apex 153 of the notch 157, while the serrated surfaces 161 are on the opposite side and it is'to be noted from an inspection of FIG. 3, that the apex 158 is substantially in alignment with a vertical plane through the axis of the debarking head 27. Consequently, the feed rolls 148 and 149 in effect, provide a generally concave surface for receiving and supporting a log to be fed to the debarking ap- 11 paratus and the novel design of these feed rolls results in an efficient and accurate feeding operation.

With particular reference to FIG. 17, there is shown the specific structural details of the pressure roll 151 which may well comprise a roll shaft 161 having suitable journals 162 and 163 on opposite ends thereof and the roll shaft 161 is also provided with opposed outwardly diverging cones 164 and 165 with the inner ends of such cones being spaced apart, as clearly shown in FIG. 17. The log engaging surface 166 of the cone 164 is smooth, while the log engaging surface of the other cone 165 is provided with a plurality of annular ribs 167 and it is also to be noted, that the roll shaft 161 between the inner ends of the cones 164 and 165 is provided with a plurality of annular ribs or serrations 168. As clearly shown in FIG. 3, the cone 165 of the pressure roll 151 having the annular ribs 167 thereon is disposed on the same side of the longitudinal center line of the path of movement of a log into the debarking apparatus as the smooth surfaces 159 on the vanes 156 of the feed roll 14-8 and the smooth surface 166 of the cone 164 is positioned on the same side of the longitudinal center line of the path of movement of the log into the debarking apparatus as the serrated portions 160 of the vanes 156 on the feed roll 148. The pressure roll 151 likewise provides a generally concave surface for engaging the log enter-ing the debarking apparatus.

With particular reference to FIG. 4, there is also provided a conveying mechanism for engaging and removing a log from the debarking apparatus of this invention and such conveying mechanism may be similar to the feeding mechanism above described and may Well comprise upright side frame members 169 which serve to support longitudinal frame members 170 on which are rotatably mounted a plurality of conveyor rolls 171 and 172. Such conveyor rolls may be similar to the feed rolls 143 and 149 above described. The side frame members 169 extend upwardly above the conveyor rolls 171 and 172 and are connected at the top by a frame member 173 and slidably mounted on the upright side frame members 169 is a cross head, not shown, which serves to rotatably support a pressure roll 174 in a position between and above the conveyor rolls 171 and 172. The pressure roll 174 may be similar to the pressure roll 151 above described and the engagement of such pressure roll 174 with a log may be controlled by a fluid pressure cylinder 175 mounted on the upper cross member 173 and connected to the cross head which supports the pressure roll 174.

In the operation of the debarking apparatus of this invention, it is assumed that the drive motors 42 and 43 are energized to drive the debarking head 27 through the friction drive rollers 44 and that the fluid pressure cylinder 25 has been operated to raise or lower the frame 14 about the pivot pin 17 and thereby center the debarking head 27 with reference to the particular log to be operated upon. It is also to be assumed that a suitable vacuum has been induced in the vaccum chambers 57, 58, 59 and 60, as well as in the outer actuating chambers 66, 72, 75 and 78 and after the application of a suitable vacuum to these chambers the vacuum connection to the fitting in the aperture 119 may be removed. Pressure roll 151 is adjusted by operation of the fluid pressure cylinder 152 to engage the pressure roll 151 with a log supported on the feed rolls 14S and 149. Operation of the feed rolls 148 and 149 will serve to move the log longitudinally toward the debarking apparatus and the leading end of the log will engage the tapered cam surface 127 on the flange 12.3 of the debarking tools 39 with the result that the tools 89 will be moved radially outwardly until the cutter bits 142 engage the surface of the log. Movement of the debarking tool 89 outwardly will, as best shown in FIG. 6, result in moving the diaphragms 64 inwardly and due to the vacuum in the outer or actuating chambers 66, '72, 75, and

all

73 an appreciable force will be applied to the debarking tools 89 through the connecting chains 11% and the arms 88 mounted on the tool shafts 81, 82, 84 and 85. If the surface of the log is substantially uniform, the debarking tools 39 rotating around the log with the cutter bits in engagement with the surface thereof will result in removing the bark from the log as the log is moved through the central opening 32 of the debarking head 27 by the feed rolls 148 and 149 and the log emerging from the debarking apparatus will engage the conveying rolls 171 and 172 and the pressure roll 174 and be removed therefrom.

In the event one of the debarking tools 89 engages a projection on the surface of the log and is thereby subjected to a sudden outward movement, the diaphragm 64 connected thereto will likewise move inwardly and will tend to rapidly increase the volume in the associated outer actuating chamber, but such increase in volume is compensated for by communication of such actuating chamber through the relatively large aperture 71 with the adjacent vacuum chamber 57. This change in volume will, however, have little if any effect on the outer actuating chamber 78 connected to the vacuum chamber 57, since the connecting aperture 7h is relatively small in cross section and offers considerable resistance to the flow of air therethrough. Consequently, the large and small apertures connecting the actuating chambers with the vacuum chambers provide equalizing means which permit substantially complete independent operation of the diaphragms with consequent control of the debarking tools 39 thereby performing a complete and uniform dcbarking operation.

The feed works described above, and including the feed rolls 148 and pressure roll 151 is particularly designed to facilitate the feeding of a log to the debarking apparatus of this invention, and this feed works serves to normally prevent rotation of the log by reason of engagement of the rotating dcbarking tools therewith, but in the event a projecting limb, knot or enlargement on the log prevents passage of the same between the ressure roll and the feed rolls, appropriate steps may be taken to permit turning of the log a sufficient distance to position the projection in such a manner that the same will pass between the pressure roll and feed rolls. Furthermore, the feed and pressure rolls are so designed as to provide for automatic recentering of the log in the event the same moves transversely out of axial alignment with the debarking head during turning of the log as mentioned above.

The above-mentioned operations are possible by reason of the provision on the feed rolls of the smooth, tapered surfaces 159 on the vanes 156, and the annular ribs 167 on the cone 165 of the pressure roll 151. During ordinary debarking operations the pressure roll 151 engages the log to hold the same in engagement with the feed rolls 148, and the serrations 160 on the vanes 156' will prevent turning of the leg as the result of engagement of the rotating debarking tools therewith. The log will normally be positioned in axial alignment with the debarking head by reason of the opposed, conical formation of both the feed rolls and the pressure roll. It is also to be noted that the annular ribs 167 on the pressure roll 151 are located on the opposite side of the mid-points of the feed rolls from the serrations 161), and consequently such annular ribs also serve to prevent turning of the log.

In the event it is desired to permit the log to turn, it is only necessary to raise the pressure roll 151 a sufiicient distance to relieve the pressure on the log, whereupon the log will turn by reason of the engagement of the rotating debarking tools therewith. When the log has reached the desired position, the pressure roll may be lowered into engagement therewith to stop turning of the log. While normally the log during turning thereof will not move transversely, due to the fact that as viewed in FIG. 3, the log turns in a clockwise direction, and consequently would tend to climb the tapered, smooth surfaces 1159 on the vanes 156 of the feed rolls 148, there is usually insufficient friction therebetween to cause transverse movement of the log. However, should such transverse movement take place, the log will then move up the tapered surfaces 159 into engagement with the annular ribs 167 on the pressure roll 151, and since these ribs will prevent turning'of the log with respect thereto, the log will therefore move along the annular ribs 167 toward the mid-point of the pressure roll and the midpoints of the feed rolls, thereby bringing the log again intoaxial alignment with the debarking head If, for any reason, the log is displaced to the left, as viewed in FIG. 3, the same may be conveniently brought into alignment with the debarking head by allowing the log to turn in the manner described above in engagement with the serrations res which will result in the log moving toward the right, since relative movement between the log and the serrations 166 is prevented, and of course during this operation the log would be in engagement with the smooth cone 166 on the pressure roll 151, which would permit the required turning movement of the log to center the same.

It will therefore be seen that the feed works provided and operated as described above is peculiar to a debarking apparatus, since during a debarking operation the log tends to rotate or turn, and this must be prevented to permit eflicient debarking operation, but in the event turn ing is desired for the purposes mentioned above, the feed works affords a unique structure for permitting this operation.

Upon completion of the debarking operation, the trailing end of the log will engage the curved surfaces 128 and 125 on the trailing edge of the flange 124 on the debarking tools $9 with the result that such debarking tools will be moved gradually inwardly until the ear 131 on each tool 39 engages the stop members 132 on the end plate 3% of the debarking head 27. This prevents a sudden inward movement of the debarking tools 89 thereby substantially eliminating a major cause of shock in such types of apparatus.

It will be seen that by the above described invention there has been provideda relatively simple, yet highly effective rotary debarking apparatus in which substantially independent control of the debarking tools is provided and in which a log may be accurately fed to the debarking apparatus and removed therefrom, the particular structure of the apparatus permitting complete and rapid removal of the bark from the entire surface of the log, regardless of projections or indentations in the surface thereof. The particular mounting of the debarking head also permits compensation for slight misalignment or irregularities and also provides for relatively quiet and vibration free operation of the apparatus.

It will be obvious to those skilled in the art that various changes may be made in the invention without departing from the spirit and scope thereof and therefore the invention is not limited by that which is shown in the drawings and described in the specification, but only as indicated in the appended claims.

What is claimed is:

1. Debarking apparatus comprising a base, a frame mounted on said base for movement in a vertical plane, means to adjust said frame vertically, a transverse horizontal opening in said frame, a debarking head rotatably disposed in said opening, said debarking head comprising inner and outer concentric cylindrical wall means, said inner wall means defining a central horizontal opening through said head for axial passage of a log, end plates secured to the opposite end edges of said inner and outer wall means to provide an enclosed space thercbetween, a plurality of pairs of yieldable rollers rotatably mounted on said frame and engaging said outer wall means to rotatably mount said head in the opening in said frame, a pair of drive motors mounted on opposite sides of said frame, friction drive means on said motors engaging said end plates to drive said head, a plurality of partitions between said inner and outer wall means defining four radially disposed actuating chambers spaced ninety degrees apart and four vacuum chambers, there being one vacuum chamber between each adjacent pair of actuating chambers, a flexible diaphragm dividing each actuating chamber into inner and outer chamber portions, a vent in one end plate communicating with each inner chamber portion and with the atmosphere, certain of said partitions each having an aperture of relatively small cross section communicating with one of said outer chamber portions and one adjacent vacuum chamber, the other of said partitions each having an aperture of relatively large cross section communicating with one of said outer chamber portions and the other adjacent vacuum chamber, a tool shaft rotatably mounted in said end plates and extending through each inner chamber portion and outwardly of one end plate, a debarking tool fixed to the outwardly extending end of each shaft, each tool comprising an elongated curved body projecting radially inwardly of said inner wall means and terminating in a bark removing means, stops on one end plate to limit inward pivotal movement of said debarking tools, an arm fixed to each shaft within each inner chamber portion, a flexible member connecting each arm and each diaphragm, a pair of diametrically spaced thrust rollers mounted on said frame and engaging the end plate on the opposite side of said head from said debarking tools, a second pair of diametrically spaced thrust rollers mounted on said frame and engaging the end plate on the same side of said head as said debarking tools, said second pair of thrust rollers being angularly spaced ninety degrees from said first pair of thrust rollers, means for feeding a log axially of said head into engagement with said debarking tools and through said central horizontal opening and conveying means engaging said log on the exit side of said head.

2. Debarking apparatus comprising a base, a frame mounted on said base for movement in a vertical plane, means to adjust said frame vertically, a transverse horizontal opening in said frame, a debarkinghead rotatably disposed in said opening, said debarking head comprising inner and outer concentric cylindrical wall means, said inner wall means defining a central horizontal opening through said head for axial passage of a log, end plates secured to the opposite end edges of said inner and outer wall means, a plurality of pairs of rollers rotatably mounted on said frame and engaging said outer wall means to rotatably mount said head in the opening in said frame, a pair of drive motors mounted on opposite sides of said frame, friction drive means engaging said end plates to drive said head, a plurality of partitions between said inner and outer wall means defining four radially disposed actuating chambers spaced ninety degrees apart and four vacuum chambers, there being one vacuum chamber between each adjacent pair of actuating chambers, a flexible diaphragm dividing each actuating chamber into inner and outer chamber portions, certain of said partitions each having an aperture of relatively small cross section communicating with one of said outer chamber portions and one adjacent vacuum chamber, the other of said partitions each having an aperture of relatively large cross section communicating with one of said outer chamber portions and the other adjacent vacuume chamber, a tool shaft rotatably mounted in said end plates and extending through each inner chamber portion and outwardly of one end plate, a debarking tool fixed to the outwardly extending end of each shaft, each tool comprising an elongated curved body projecting radially inwardly of said inner shell and terminating in a bark removing means, stops on said one end plate to limit inward pivotal movement of said debarking tools, an arm fixed to each shaft within each inner chamber portion, a flexible member connecting each arm and each diaphragm, thrust rollers mounted on said frame and engaging the end plates on said head, means for feeding a log axially of said head into engage- 2 5 ment with said debarking tools and through said central horizontal opening and conveying means engaging said log on the exit side of said head.

3. Debarking apparatus comprising a base, a frame mounted on said base for movement in a vertical plane, means to adjust said frame vertically, a transverse horizontal opening in said frame, a debarking head rotatably disposed in said opening, said debarking head comprising inner and outer concentric wall means, said inner wall means defining a central horizontal opening through said head for axial passage of a log, end plates secured to the opposite end edges of said inner and outer wall means, means to rotatably mount said head in the opening in said frame, means to drive said head, a plurality of partitions between said inner and outer wall means defining four radially disposed actuating chambers and four vacuum chambers, there being one vacuum chamber between each adjacent pair of actuating chambers, a flexible diaphragm dividing each actuating chamber into inner and outer chamber portions, certain Of said partitions each having an aperture of relatively small cross section communicating with one of said outer chamber portions and one adjacent vacuum chamber, the other of said partitions each having an aperture of relatively large cross section communicating with one of said outer chamber portions and the other adjacent vacuum chamber, a tool shaft rotatably mounted in said end plate and extending through said each inner chamber portion and outwardly of one end plate, a debarking tool fixed to the outwardly extending end of each shaft, each tool comprising an elongated curved body projecting radially inwardly of said inner shell and terminating in a bark removing means, stops on said one end plate to limit inward pivotal movement of said debarking tools, an arm fixed to each shaft within each inner chamber portion, a fiexible member connecting each arm and each diaphragm, means for feeding a log axially of said head into engagement with said debarking tools and through said central horizontal opening and conveying means engaging said log on the exit side of said head.

4. Debarking apparatus comprising a base, a frame mounted on said base for movement in a verticalplane, means to adjust said frame vertically, a transverse horizontal opening in said frame, a debarking head rotatably disposed in said opening, said debarking head comprising inner and outer wall means, said inner wall means de-' fining a central horizontal opening through said head for axial passage of a log, end plates secured to the opposite end edges of said inner and outer wall means, means to rotatably mount said head in the opening in said frame, means to drive said head, a plurality of partitions between said inner and outer wall means defining four radially disposed actuating chambers and four vacuum chambers, there being one vacuum chamber between each adjacent pair of actuating chambers, a flexible diaphragm dividing each actuating chamber into inner and outer portions, certain of said partitions each having an aperture of relatively small cross section communicating with one of said outer portions and one adjacent vacuum chamber, the other of said partitions each having an aperture of relatively large cross section communicating with one of said outer portions and the other adjacent vacuum chamber, a tool shaft rotatably mounted in said end plates and extending through each inner portion and outwardly of one end plate,a debarking tool fixed to the outwardly extending end of each shaft, each tool comprising a body extending inwardly of said inner wall means and terminating in a bark removing means, stops on said one end plate to limit inward pivotal movement of said debarking tools, an arm fixed to each shaft within each inner chamber, a flexible member connecting each arm and each diaphgram and means for feeding a log axially of said head into engagement with said debarking tools and through said central horizontal open mg.

5. Debarking apparatus comprising a base, a. frame mounted on said base for movement in a vertical plane, means to adjust said frame vertically, a transverse horizontal opening in said frame, a debarking head rotatably disposed in said opening, said debarking head comprising inner and outer wall means, said inner wall means defining a central horizontal'opening through said head for axial passage of a log to be debarked, end plates secured to the opposite end edges of said inner and outer wall means, means to rotatably mount said head in the opening in said frame, means to drive said head, a plurality of partitions between said inner and outer shells defining a plurality of actuating chambers and vacuum chambers, there being one vacuum chamber between each adjacent pair of actuating chambers, a flexible diaphragm dividing each actuating chamber into inner and outer portions, certain of said partitions each having an aperture of relatively small cross section communicating with one of said outer portions and one adjacent vacuum chamber, the other of said partitions each having an aperture of relatively large cross section communicating with one of said outer portions and the other adjacent vacuum chamber, each inner portion having a vent opening, a tool shaft rotatably mounted in said end plates and extending through each inner portion and outwardly of one end plate, a debarking tool fixed to the outwardly extending end of each shaft, each tool comprising a body extending inwardly of said inner wall means and terminating in a bark removing means, stops on one end plate to limit inward pivotal movement of said debarking tools, an arm fixed to each shaft within each inner chamber portion, a flexible member connecting each arm and each diaphragm and means for feeding a log axially of said head into engagement with said debarking tools and through said central horizontal opening.

6. Debarking apparatus comprising a base, a frame mounted on said base for movement in a vertical plane, means to adjust said frame vertically, a transverse horizontal opening in said frame, a debarking head rotatably disposed in said opening, said debarking head comprising inner and outer wall means, said inner wall means defining a central horizontal opening through said head for axial passage of a log to be debarked, end plates secured to the opposite end edges of said inner and outer wall means, means to rotatably mount said head in the opening in said frame, means to drive said head, a plurality of partitions between said inner and outer Wall means defining radially disposed actuating chambers and vacuum chambers, there being one vacuum chamber between each adjacent pair of actuating chambers, a flexible diaphragm dividing each actuating chamber into inner and outer chamber portions, certain of said partitions each having an aperture of relatively small cross section communicating with one of said outer chamber portions and one adjacent vacuum chamber, the other of said partitions each having an aperture of relatively large cross section communicating with one of said outer chamber portions and the other adjacent vacuum chamber, said inner chamber portions having vent openings, a tool shaft rotatably mounted in said end plates and extending through each inner chamber portion and outwardly of one end plate, a debarking tool fixed to the outwardly extending end of each shaft, each tool comprising an elongated body extending inwardly of said inner wall means and terminating in a bark removing means, an arm fixed to each shaft within each inner chamber portion, means connecting each arm and each diaphragm so that the tools are urged inwardly in response to the vacuum conditions in said outer chamber portions and means for feeding a log axially of said head into engagement with said debarking tools and through said center horizontal opening.

7. Debarking apparatus comprising a base, a frame mounted on said base for movement in a vertical plane, means to adjust said frame vertically, a transverse horizontal opening in said frame, a debarking head rotatably disposed in said opening, said debarking head comprising inner and outer wall means, said inner wall means defining a central horizontal opening to said head for axial passage of a log, end plates secured to the opposite end edges of said inner and outer wall means, means to rotatably mount said head in the opening in said frame, means to drive said head, a plurality of partitions between said inner and outer wall means defining radially disposed actuating chambers and vacuum chambers, there being one vacuum chamber between each adjacent pair of actuating chambers, a flexible diaphragm dividing each actuating chamber into inner and router portions, certain of said partitions each having an aperture of relatively small cross section communicating with one of said outer portions and one adjacent vacuum chamber, the other of said partitions each having a relatively large cross section communicating with oneof said outer portions and the other adjacent vacuum chamber, a tool shaft rotatably mounted in said end plates and extending through each inner chamber portion, a debarking tool fixed to each shaft, each tool comprising an elongated body projecting inwardly of said inner Wall means and terminating in a bark remover, an arm fixed to each shaft within each inner chamber and means connecting each arm and each diaphragm so that said tools are urged inwardly in response to the vacuum conditions in said outer portions.

8. A rotatable debarking head foruse in debarking apparatus, said debarking head comprising a hollow ring having a central horizontal opening for axial passage of a log, a plurality of actuating chambers and vacuum chambers in said head, there being at least one vacuum chamber for each actuating chamber, a flexible diaphragm within each actuating chamber, each of said actuating chambers communicating with a vacuum chamber, a tool shaft rotatably mounted in said head, a debarking tool fixed to each shaft, each tool comprising an elongated body projecting radially inwardly of said opening and terminating in a bark remover, an arm fixed to each shaft and means connecting each arm and each diaphragm so that each tool is urged inwardly in response to vacuum conditions in said chambers.

9. A rotatable debarking head for use in a debarking apparatus, said debarking head comprising a hollow ring having a central horizontal opening for axial passage of a log, a plurality of actuating chambers and vacuum chambers in said head, a flexible diaphragm within each actuating chamber, each of said actuating chambers communicating with one vacuum chamber through an aperture of relatively small cross section, each of said actuating chambers communicating with another vacuum chamber through an aperture of relatively large cross section, a tool shaft rotatably mounted in said head, a debarking tool fixed to each shaft, each tool extending inwardly of said opening and terminating in a bark remover and means connecting each arm and each diaphragm.

N. A debarking apparatus as defined in claim in which each of said diaphragms comprises a disk of flexible material, means removably mounting said disk Within said actuating chamber to provide a fluid tight partition between said inner and outer chamber portions, a rigid plate secured to the central portion of said diaphragm, each of said arms comprising a hub fixed to the associated tool shaft, a radially projecting boss on said hub, the outer portion of said boss being reduced in thickness and shaped to provide an arcuate rib having opposite side surfaces and an arcuate peripheral surface concentric with the axis of said tool shaft, said boss having a transverse aperture spaced from one end of said rib, said flexible member comprising a chain having one end secured to said rigid plate on said diaphragm and the opposite end secured to said boss by a pin extending through said aperture, said chain including cross members and side links, the cross members of said chain engaging said peripheral surface and the side links of said chain overlapping the side surfaces of said rib.

18 11. A debarking apparatus as defined in claim 5 in which each of said diaphragms comprises a disk of flexible material, means movably mounting said disk within the associated actuating chamber to provide a fluid tight partition, each of said arms including a hub fixed to the associated tool shaft, a radially projecting boss on said hub, the outer portion of said boss being reduced in thickness and shaped to provide an arcuate rib having opposite side surfaces and an arcuate peripheral surface concentric with the axis of said tool shaft, said flexible member comprising a chain having one end se cured to said diaphragm and means securing the opposite end to said boss, said chain including members and side links, the cross members of said chain engaging said peripheral surface and the side links of said chain overlapping the side surfaces of said rib.

12. A debarking apparatus as defined in claim 5 in with each of said diaphragms comprises a disk of flexible material, means removably mounting each disk within an associated actuating chamber to provide a fluid tight partition, each of said arms including a hub fixed to the associated tool shaft, a radially projecting boss on said hub, the outer portion of said boss having an arcuate peripheral surface concentric with the axis of said tool shaft, said flexible member having one end secured to said diaphragm and means securing the opposite end to said boss, and said flexible member engaging said peripheral surface.

13. A debarking apparatus as defined in claim 5 in which each of said debarking tools includes a hub fixed to the associated tool shaft, said body extending inwardly from said hub and comprising opposed flanges and an outwardly projecting rib defining a cross section of generally T-shape, said body terminating in a cutter receiving portion, the flange remote from the adjacent end plate of said head being tapered outwardly to the end of said body to provide a leading edge cam surface for engaging the leading end of an advancing log to move said. body about the axis of said shaft outwardly of said log, the opposite flange being tapered outwardly to the end of said body to provide a trailing cam surface, said trailing cam surface serving to engage the trailing end of a log to permit gradual inward movement of said body about the axis of said shaft, a generally rectangular recess in the cutter receiving portion of said body, a circular recess communicating with said rectangular recess, a cutter means disposed in said rectangular recess, a circular boss on said cutter means being disposed in said circular recess, the depth of said circular recess being greater than the height of said boss, said boss having a threaded recess, said cutter receiving portion having an aperture and a threaded member extending through said aperture into said threaded reces to secure said cutter means to said tool body.

14. A debarking apparatus as defined in .claim 5 in which each of said debarking tools includes a hub fixed to the associated tool shaft, said body extending inwardly from said hub, bark removing means at the terminal end of said body, the side of said body remote from the adjacent end plate of said head being tapered outwardly to the end of said body to provide a leading edge cam surface for engaging the leading end of an advancing log to move said body about the axis of said shaft outwardly of said log and the opposite side of said body being tapered outwardly to the end of said body to provide a trailing cam surface, said trailing cam surface serving to engage the trailing end of a log to permit gradual inward movement of said body about the axis of said shaft.

15. In a log debarking machine a rotary head having a central passage for the axial movement of logs therethrough, a plurality of arms carried by said head and mounted for movement toward the center of said passage, bark removing means mounted on the inner ends of said arms, individual vacuum operated means carried by said head, means for applying a vacuum to each of said vacuum operated means, each of said vacuum operated means being connected with one of said arms for moving the same toward the center of said passage to effect debarking and means for rotating said head, whereby by reason of the vacuum actuation of said arms the engaging pressure between each of said bark removing means and the log will be maintained constant irrespective of outward or inward movement of any or all of said bark removing means as the result of variations in log diameter or contour.

16. In a log debarking machine a hollow rotor having a central passage through which logs to be debarked are passed, means for rotating said rotor, said rotor having a plurality of chambers therein, a plurality of arms carried by the rotor and mounted for movement toward and away from the axis of the rotor, bark removing means mounted on the inner ends of each arm, there being at -least one chamber for each arm, a diaphragm within each chamber dividing the same into two portions, one portion being vented to atmosphere, means for applying a vacuum to the other portion, and means operably connecting each diaphragm with an associated arm for urging said arms inwardly for debarking purposes responsive to the vacuum conditions in aid other portions, whereby by reason of the vacuum actuation of said arms the engaging pressure between each of said bark removing means and the log will be maintained constant irrespective of outward or inward movement of any or all of said bark removing means as the result of variations in log diameter or contour.

17. A debarking apparatus comprising a base, a frame mounted on said base, a generally circular debarking head rotatably mounted on said frame, said head having a central horizontal opening therethrough for axial passage of a log to be debarked, a plurality of debarking tools mounted on said head for radial movement, means for yieldably urging said tools into engagement with a log passing through said opening, means to drive said head to rotate said tools around said log to remove bark therefrom, the rotation of said tools tending to turn said log, means for feeding a log axially of said head into engagement with said tools and through said horizontal opening comprising a plurality of horizontally spaced feed rolls disposed transversely of the path of movement of said log, said feed rolls being formed as opposed cones diverging outwardly from the mid-point, at least certain of said feed rolls having circumferentially spaced radially projecting vanes disposed longitudinally of each cone, the surface of each vane on the side of said feed rolls toward which said log tends to turn being smooth and the surface of each vane on the opposite side being serrated, a rotatable pressure roll mounted for vertical movement toward and away from said feed rolls, said pressure roll being formed as opposed cones diverging outwardly from the mid-point, the

cone on said pressure roll adjacent said smooth vanes having axially spaced annular ribs thereon and the cone on said pressure roll adjacent said serrated vanes being smooth, whereby upon movement of said pressure roll a limited distance away from said feed rolls to permit said log to turn any transverse movement of said log along said smooth vanes will raise said log into engagement with said ribs and turning of said log in engagement with said ribs will cause said log to turn and slide on said smooth vanes toward the mid-point and any transverse movement of said log into engagement with said serrated vanes and said smooth cone will as a result of turning of the log in engagement with said serrated vanes cause said log to move toward the mid-point while turning and sliding on said smooth cone.

References Cited by the Examiner UNITED STATES PATENTS 2,095,833 10/37 Rockwell.

2,625,968 1/53 Eklund et al.

' 2,707,858 5/55 Norton et al 74-206 X 2,749,952 6/56 League.

2,821,220 1/58 Nicholson.

' 2,880,771 4/59 Annis.

2,908,302 10/59 Mullis.

LESTER M. SWINGLE, Primary Examiner.

WALTER A. SCHEEL, EARL EMSHWILLER,

WILLIAM W. DYER, JR., Examiners. 

15. IN A LOG DEBARKING MACHINE A ROTARY HEAD HAVING A CENTRAL PASSAGE FOR THE AXIAL MOVEMENT OF LOGS THERETHROUGH, A PLURALITY OF ARMS CARRIED BY SAID HEAD AND MOUNTED FOR MOVEMENT TOWARD THE CENTER OF SAID PASSAGE, BARK REMOVING MEANS MOUNTED ON THE INNER ENDS OF SAID ARMS, INDIVIDUAL VACUUM OPERATED MEANS CARRIED BY SAID HEAD, MEANS FOR APPLYING A VACUUM TO EACH OF SAID VACUUM OPERATED MEANS, EACH OF SAID VACUUM OPERATED MEANS BEING CONNECTED WITH ONE OF SAID ARMS FOR 